A fully remote, home-based randomized controlled trial is testing whether tirzepatide (Zepbound), a dual glucose-dependent insulinotropic polypeptide (GIP)/glucagon-like peptide-1 (GLP-1) receptor agonist approved for type 2 diabetes, obesity, and obstructive sleep apnea, can reduce symptoms of long COVID over 12 months, according to information from the trial’s sponsors. The study, LoCITT-T (Long COVID Treatment Trial-Tirzepatide), is being led by researchers at Scripps Research on the Long COVID Treatment Trial (LoCITT) platform funded by the Schmidt Initiative for Long Covid, and aims to enroll up to 1,000 U.S. adults, with participants completing every step of the trial from home.
Why long COVID has resisted a targeted therapy
Long COVID, medically defined as post-COVID-19 condition or post-acute sequelae of SARS-CoV-2 infection (PASC), affects an estimated 400 million people worldwide. Symptoms are heterogeneous but include persistent fatigue, cognitive dysfunction (“brain fog”), post-exertional malaise, dysautonomia, and cardiorespiratory symptoms. Multiple mechanisms have been proposed, including viral persistence, autoimmunity, endothelial dysfunction, mitochondrial dysfunction, and chronic neuroinflammation. No FDA-approved treatments exist for long COVID as a syndrome. Most clinical trials to date have tested single mechanisms in narrow subpopulations, and few have been designed to reach the many patients whose illness prevents them from attending clinic-based studies.
Why tirzepatide is the intervention being tested
Tirzepatide is a once-weekly subcutaneous injection that activates both glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. Beyond its established effects on appetite, insulin sensitivity, and weight loss, GLP-1 receptor agonists as a class have documented anti-inflammatory activity, including effects on markers of systemic inflammation and on microglia, the resident immune cells of the central nervous system. Preclinical and early clinical evidence suggest these agents can reduce neuroinflammation, which has been implicated in the cognitive and post-exertional symptoms of long COVID. Because tirzepatide’s safety and side-effect profile are already well-characterized from its approved indications, testing it in a new setting can proceed faster than for a novel compound. This approach, testing an approved medicine for a new use, is called drug repurposing.
How the trial is designed
LoCITT-T is a fully remote, randomized, placebo-controlled trial with a target enrollment of up to 1,000 U.S. adults with long COVID. Participants are randomized to weekly tirzepatide or matched placebo, with study medications shipped directly to their homes. The active treatment period lasts approximately 12 months. Every step of the trial (screening, eligibility verification, consent, symptom questionnaires, medication ordering, and follow-up) is conducted through the MyDataHelps app or by email, phone, or video, and caregivers can assist bedbound participants. All participants receive a Garmin wrist-worn activity tracker and smart scale to enable continuous, real-world collection of health metrics. A subset of approximately 50 participants is enrolled in an at-home blood-sampling cohort for exploratory biomarker analysis.
The primary hypothesis is that tirzepatide reduces long COVID symptoms via anti-inflammatory effects, particularly on neuroinflammation. Secondary outcomes include changes in hyperglycemia, blood pressure, body weight, and oxidative stress markers, as well as objective activity data from wearable devices. As of December 2025, eligibility verification for the trial has closed, and results are expected approximately 14 months after recruitment ends.
Why a home-based design matters
Many people with long COVID are too exhausted or symptomatic to travel repeatedly to a research center, and traditional in-person trials effectively exclude them. This is a substantial methodological limitation: the patients most affected by the illness are the ones most likely to be missed by conventional research designs, biasing results toward milder cases. According to the trial’s leadership, only two long COVID trials to date have been fully accessible from home, out of hundreds run globally. By moving screening, consent, drug delivery, symptom assessment, and biomarker collection to the participant’s home, LoCITT-T aims to reach patients who would otherwise be excluded, including those who are bedbound. Trial materials can be filled out with caregiver help, and communication with study staff happens through the participant’s preferred channel.
What the trial cannot answer
LoCITT-T is a hypothesis-testing trial. Tirzepatide may improve long COVID symptoms, may show no benefit, or may benefit some patients but not others. The trial’s remote design allows broader inclusion but also means that symptom outcomes rely more heavily on patient-reported measures and wearable data than on in-clinic assessments. If tirzepatide is found to help, the trial cannot by itself distinguish whether the benefit comes from direct anti-inflammatory action, from weight loss and metabolic improvements, or from some combination. Head-to-head comparisons with other candidate long COVID interventions, and trials in more diverse international populations, will be needed. A positive result would still require regulatory review before tirzepatide could be prescribed for long COVID.
Why this trial matters even if tirzepatide does not work
Beyond the specific drug being tested, LoCITT-T is being watched as a template for how to run clinical research in conditions that leave patients unable to travel. Myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS), postural orthostatic tachycardia syndrome (POTS), and other post-viral or dysautonomic conditions share this challenge, and results from LoCITT-T will inform whether fully remote trial platforms can produce evidence of sufficient quality to change clinical practice. The trial is funded by the Schmidt Initiative for Long Covid, a nonprofit founded in 2023 by Eric and Wendy Schmidt to expand long COVID clinical care and research globally. Study medication (tirzepatide and matched placebo) is supplied by its manufacturer, Eli Lilly.
Julia Moore Vogel, co-principal investigator of LoCITT-T at Scripps Research, has described the trial as designed to be completed by participants from home, including by those who are bedbound, expanding access to research for the patients most affected by post-viral illness. For anyone living with long COVID today, tirzepatide is not a treatment their doctor can prescribe for this indication. For now, the practical options are to stay informed and, if appropriate for their situation, ask their care team about reputable clinical trials.
References
- Long COVID Treatment Trial-Tirzepatide (LoCITT-T). Scripps Research. longcovid.scripps.edu/locitt-t. ClinicalTrials.gov identifier: NCT07128082.